About Gallinula tenebrosa Gould, 1846
The dusky moorhen, scientifically named Gallinula tenebrosa Gould, 1846, is a medium-sized bird that is slightly smaller than the purple swamphen. Populations in New Guinea are smaller than the Australian race, measuring 25–32 centimetres (9.8–12.6 in) in length, while the Australian race measures 34–38 centimetres (13–15 in). On average, adult males generally weigh around 570 grams, and adult females weigh 493 grams. Adult dusky moorhens are mainly dark grey-black, with a browner tinge on their upper parts. They have a red frontal shield and a red bill with a yellow tip, similar to their Eurasian relative. However, they lack the white flank line that common moorhens have, and their legs are orange-yellow instead of yellow. The Australian subspecies is larger and paler than the other two subspecies. In autumn and winter, the frontal shield of females and young males grows duller in color. During the warmer breeding season, the shield becomes brighter again for both sexes. This species occurs in Australia, New Guinea, Borneo and Indonesia. Some vagrant, non-breeding birds can also be found in New Zealand. In Australia, they are found across the eastern states of Victoria, New South Wales and Queensland, extending as far north as Cooktown. They also live in eastern South Australia and the south-western tip of Western Australia. They are present in parts of Tasmania and South Australia as well, but are uncommon there. Their natural distribution range includes wildlife parks such as Currumbin Wildlife Sanctuary and the Brisbane Botanic Gardens. Dusky moorhens inhabit wetland habitats, with a preference for freshwater marshes and swamps. They are rarely found far from these areas except when foraging in nearby vegetation. They also live in urban parks such as the Gold Coast Regional Botanic Gardens, and are often found in dams and on river banks. They require open water, usually with some cover such as grass, reeds, and other vegetation. In south-east Queensland, dusky moorhens are more likely to be found in areas with taller vegetation, more attached aquatic vegetation, and a larger number of purple swamphens. This indicates that the availability of food and other resources affects their numbers and distribution in wetlands. They usually live in low-lying areas, though one pair has been recorded as high up as 1,580 metres in New Guinea, and this pair was likely separated from its flock. These birds do not often migrate long distances, and may remain in the same location for eight years or more. They may move to different locations within their range when resources become scarce. Young birds leave their birthplace in autumn and spring, and may be found in locations not normally frequented by adult birds.
